No longer an HD radio virgin

[MikeShannon914]

Backstory...bought an in-dash AM-FM-CD/CDRW(MP3)/HD Radio unit about 18 months ago. JUST NOW got around to messing with it. The idea here is to keep the factory radio as-is, and install this new unit in the glove compartment. (This is one of those cars that would have a gaping hole if you took out the factory unit, like a triple-DIN or something, and no one makes a kit for it. Besides, it would render the steering wheel radio controls obsolete.) FYI, the unit is made by "Dual" and was $99 or so at Fry's.

Still got some hardwiring to do (and locating an antenna splitter,) but for now, it's on and working. HD locks on quite well, and even tuned in some distant (non-HD) rimshots I usually don't get. (Might have been the weather.) Anyway, noticed a couple of things...one, the sound of the "normal" station gets some fairly dramatic improvement when the HD locks on. (Even 35-yr old old tapes of Casey Kasem reruns over KLUV had some great depth to them in HD.) The other thing is that there's about a 0.5 second delay from the HD station when compared to my portable radio playing nearby. In other words, KLUV-HD1 is a half-sec slower than raw KLUV-FM. It's no issue for me, but what causes that?

"In the final analysis," I'll ultimately end up with AM, FM, HD, a CD player that plays .mp3-formatted CD's along with conventional ones, and I've piped in the XM unit AND still have a place to plug in an iPod. Sheesh, I guess that's what it takes to deal with This Thing We Call DFW Radio...

 

[radi0avenger]

I don't know how CBS does it, but the radio cluster I worked for had to set their analog transmitters in delay approx 8 sec to match the digital encoding and decoding...so when you switched, it'd be relatively seamless. This was done by ear, and probably isn't an exact science. KLUV may have gotten theirs off by a half second or so. I bet if you listened, the others may be in varying degrees of lag in either direction. It was as close as could be done at the time they were setup.

There's no exact 8 seconds, so you cant just set an "8 second" delay. Some of them are 7.52, some are 8.21. So yeah, getting it EXACTLY on is difficult at best.

 

[Tom Wells]

Odds are ten to one you've utterly destroyed whatever little AM sensitivity you had.
Those splitters care not and are not designed to maintain proper impedances for AM signals.
As antennas now are usually totally insufficient for AM, any reduction in AM signals to the receiver
virtually ensures you won't ever be able to use AM in the tradional long-range mode, but will be limited to local market
full quieting signals, and many of them would be too weak or hissy for most to tolerate.

If the splitter is properly designed, there would be an input AND output trimmer capacitor to tweak for the AM pass-through.
Otherwise your AM now only picks up local market signals "just like FM".

Strangely, this was the way the Third Reich wanted their citizens' radios to work, so they were made to only be able to pick up strong local signals from the Reich's MW service.
Why would you EVER want to listen to a signal from way over "there"?
I had an AM only radio in one car, and could not tolerate the loss created by a cheap FM converter inline.
I found a factory in-dash AM/FM for it, because superior AM radio performance is important to me.

I'd love to know how the two radios compare for weak AM signals.
And bygosh, what are the 2 radios? Are you leaving BOTH working somehow?

 

[fybush]

Strangely, this was the way the Third Reich wanted their citizens' radios to work, so they were made to only be able to pick up strong local signals from the Reich's MW service.
Why would you EVER want to listen to a signal from way over "there"?

I never thought I'd need to invoke Godwin's Law in the context of an HD Radio discussion, and yet there it is.

Go figure...

 

[Tom Wells]

Holy Arcing Fuzzy Phasors, Batman! TIO territory!

I knew exactly where this might go but when else has engineered radio deafness been acceptable and even mandated?
I'm just telling the truth, and speaking as was permitted before such constructs as Godwin's Law permitted us to dismiss information
as "outlandish" or from a disreputable viewpoint. You do accept the factual aspect of the info, yes?
I've stored the data mentally with no particular flavor, but "useful as reference".

I only think it's "interesting" and from an engineering standpoint, that we adopt and accept stange limitations to effectiveness of
a technology such as radio for various reasons, not all of them good.

While I'm no fearmongerer, I do believe the intention all along has been to degrade the immediate, long range, traditional abilities of
radios as these are only liabilities to media and government.

I've spent some time today doing an AM RF alignment on a 1972 Motorola car radio, and it makes any new car radio seem deaf.

 

[johndavis]

I've spent some time today doing an AM RF alignment on a 1972 Motorola car radio, and it makes any new car radio seem deaf.

That's a lot of time and effort into listening to a band with no compelling programming.

 

[Tom Wells]

I've spent some time today doing an AM RF alignment on a 1972 Motorola car radio, and it makes any new car radio seem deaf.

That's a lot of time and effort into listening to a band with no compelling programming.

I enjoy compelling programming EVERY night on my way to work, and my favorite choices for music are on AM.
They sound great most of the time, and are hundreds of miles away.
I wanted to sharpen the rf section, I am pleased to report it is sharper and now equal sensitivity across the whole band.

Perhaps it's your location, radio, or unruly electronics that make such choices unavailable to you.

 

[dismuke]

Strangely, this was the way the Third Reich wanted their citizens' radios to work, so they were made to only be able to pick up strong local signals from the Reich's MW service.
Why would you EVER want to listen to a signal from way over "there"?

This was something I had not heard about before. So when I read your posting, I did a quick google search and found this article which talks about this and radio in Nazi Germany in quite a bit of detail:

http://www.transdiffusion.org/rmc/features/hitlers_radio.php

However, even the deliberately weak radio sets could still pick up foreign broadcasts at night on drift. So, as a result, to quote from the article:

" As hostilities broke out between Germany and the Allies in September 1939, listening to enemy radio stations became punishable by a sentence in a concentration camp. All radios sold came with a chilling warning attached to the tuning knob, “Think about this: listening to foreign broadcasts is a crime against the national security of our people. It is a Führer order punishable by prison and hard labour.”

Later in the war the Gestapo was instructed to execute anyone discovered listening to enemy radio stations, and ran a particularly vindictive campaign where it advertised for sale radios with short wave bands and then arrested and shot anyone who was duped into buying one as a traitor."

Pretty chilling.

I, for one, thank you for posting it as I learned something as a result.

Of course, the difference here is the similarities are strictly technical. Today's dumbing down of radio sets is simply because enough people don't give a darn to notice and demand something better - not some sort of censorship. But the kind of stuff described in the article still goes on, of course. The Cuban government goes through a lot of effort to jam foreign broadcasts - and owning a satellite dish is illegal in Iran.

 

[dfaulkner]

Wanted to join the AM Radio part of this discussion...I purchased a radio from Radio Shack on Friday. It's called "extreme range" on the box & "high performance" on the receipt. It's the closest thing to the old GE SuperRadio that I've seen lately. It has a digital readout instead of the long analog dial the SuperRadios had.
But on the "wide" bandwith setting the AM sounds like AM should (just about the same clarity & fedelity as FM) Haven't had much time for DXing with it yet, but I've heard KOA, XEG, WOAI, WWL, & KOMA (that's their old calls, it changed when they went News/Talk, I think it's KOKC now.) There's a spanish station that's loud & clear on 1570 at night (maybe XERF is still blasting...)

 

[dfaulkner]

Wanted to say thanks to Tom Wells & Dismuke for the fascinating bit of radio history in this thread.

 

[dismuke]

That's a lot of time and effort into listening to a band with no compelling programming.

That's a matter of personal taste, isn't it?

Personally, the only time I ever tune into FM anymore is on the very rare occasion I check out what is playing on WRR. KNTU broadcasts Riverwalk Jazz with the Jim Cullum band out of San Antonio on Saturday - but I rarely listen as I am usually preoccupied with something else. Other than that, 99.5 percent of what is on FM is of zero interest to me. For me, the pickings aren't always that wonderful on AM either. But if I could only have one radio band in my car, it would definitely be AM. If I had nothing but FM, prior to the WBAP simulcast, I would probably rarely turn the thing on at all and just listen to mp3s or Internet stations on my smartphone whenever I am driving around town.

 

[OHTBGH]

I had just got back from Tulsa last week and was spining the JVC around the dial while driving. I picked up KOKC I think in HD and some others. I had not known that KLAK was in HD and it pinged it and came in quite well.

The two strangest things that happened:

1) Going up I could receive WBAP-FM crystal clear all the way up to Atoka. Yet, I have issues picking it up here! ;D

2) Coming Back I had KRLD-AM in HD from McCalister all the way back to Dallas and it did not drift once!

I got one station in Tulsa in FM HD but I can't remember what it was! They haven't embraced it much there.

Oh well, I'm still loving the radio! Oh and welcome to the 21st century Mike! ;D

- BGH

 

[Jay Walker]

The other thing is that there's about a 0.5 second delay from the HD station when compared to my portable radio playing nearby. In other words, KLUV-HD1 is a half-sec slower than raw KLUV-FM. It's no issue for me, but what causes that?

Mike one of the strange things I've noticed with the current crop of HD receivers in the analog mode only, there is a split second delay between the audio out on the HD capable and my Bose analog. I "think" that there is some form of analog delay in the non-HD mode. However if you check stations, such as JACK in HD you'll find the diversity blend is bang on between multiple receivers regarding HD/analog blending. I always thought that the HD was a strange little box even in the analog mode with the apparent delay between my analog Bose. The blending time constant is measured to the frame level for "perfect time alignment". Typically using the same processor for HD and analog minus the analog clipping the time adjust is around 8.0712540 seconds. Depending of course on how many services you provide on the carrier. Currently we are running HD1/2/3 on some stations.
That's getting it within a gnat's a$$ close...

Best regards and happy listening. And a shameless plug for the "Sound of the Strip" on 100.3 HD-2 which I have the pleasure of voicing. Quite a change from my days as the image voice of the Eagle LOL.
Jay Walker

 

[Jay Walker]

One more item Mike, CBS 100.3 now has "The Indie-Verse" on as an HD-3 service from a former internet only service. Even with the bit reduction on HD-3 it is a serviceable signal and is fun to listen to if you are into the indie scene.
Shameless plugs end now...

Jay Walker